Method and device for enabling testing of a communication node

ABSTRACT

The embodiments herein relate to a method performed by a testing device (101) for enabling testing of a communication node (103). The testing device (101) measures a test parameter associated with RF characteristics of the communication node (103) when it is located at a test location (105) during a first condition. The communication node (103) is configured with a node setting during the measurement in the first condition. The testing device (101) measures the test parameter associated with the RF characteristics of the communication node (103) when it is located at the test location (105) during a second condition. The communication node (103) is configured with the same node setting in the second condition as in the first condition. The testing device (101) checks whether a result parameter associated with the test parameter measured during the first and second condition fulfills a requirement.

TECHNICAL FIELD

Embodiments herein relate generally to a testing device and a methodperformed by a testing device. More particularly the embodiments hereinrelate to enabling testing of a communication node.

BACKGROUND

Active Antenna Systems (AAS) is an important part of the evolution ofthe Long Term Evolution (LTE) and an essential part of the FifthGeneration (5G) mobile communication. AAS is a generic term that isoften used to describe radio base stations that incorporate a largenumber of separate transmitters and antenna elements that can be usedfor Multiple Input Multiple Output (MIMO) and beamforming as anintegrated product. MIMO enables multiplying of the capacity of a radiolink by using multiple input antennas and multiple output antennas.Beamforming can be described as a signal processing technique used forcontrolling the directionality of transmission and reception of radiosignals. 3GPP defines an AAS base station as a “BS system which combinesan Antenna Array with an Active Transceiver Unit Array and a RadioDistribution Network” (3GPP TS 37.105 V13.0.0 (2016 March), Release 13).According to the 3GPP, an AAS has a radiation pattern which may bedynamically adjustable. In a “normal” base station, i.e. a base stationwhich is a non-AAS base station, the radio equipment and the antenna areseparated. In addition, a normal base station does not have capabilityof advanced antenna features such as an AAS base station.

AAS will be one of the key aspects of 5G as the industry moves higher upin frequency and more complex array antenna geometries are needed toachieve the desired link budget. At higher frequencies (e.g. 15 GHz, 28GHz or higher), propagation losses are much greater than in currentlyused frequency bands (e.g. around 1-2 GHz). Furthermore, it is envisagedthat base station transmissions will take place within higher bands inthe microwave and millimeter-wave region. Since the transmit power ofboth base stations and user equipment is limited by physical constraintsand considerations such as Electro-Magnetic Fields (EMF) for basestations and Specific Absorption Rate (SAR) for user equipment, it isnot possible to compensate the increased penetration losses and providesufficient Signal-to-Interference+Noise Ratio (SINR) within widerbandwidths (wider than the normal bandwidths which are around e.g. 1-20MHz) simply with increased transmit power. In order to achieve the linkbudgets required for high data rates (e.g. 1 Gbit/s), beamforming willbe necessary. It is therefore expected that integrated active arrayswill become a mainstream base station building practice in the 5G era.

It is envisaged that New Radio (NR) and 5G will operate in higherfrequency bands than today. For example, 4 Giga Hertz (GHz) is discussedfor first systems in Japan, whilst the World Radio CommunicationConference 2019 (WRC19) may allocate spectrum up to 6 GHz. Further intothe future, it is envisaged that the International TelecommunicationUnion (ITU) and/or regional regulators may allocate microwave andmillimeter wave spectrum in the range 10-100 GHz.

Antennas, base stations, AAS etc. may be tested to ensure that they meetspecifications or simply to characterize it. Parameters that may bemeasured during testing may be for example transmit power, radiatedunwanted emission, antenna gain, radiation pattern, beam width,polarization, impedance etc. A test may be performed in differentranges, such as far-field range, near-field range, free-space range,etc.

In a far-field test range, the testing device (also referred to asAntenna Under Test (AUT)) is placed in far field of a probe antenna (theprobe antenna is an antenna which can transmit or receive power to/fromthe testing device, and which has a known radiation pattern andcharacteristics). In a far-field, the testing device's radiation patterndoes not change shape with the distance between the testing device andthe probe antenna.

In a near-space range, the testing device and the probe antenna arelocated close to each other.

A free-space range is a measurement location designed to simulatemeasurements that would be performed in space, i.e. where reflectedwaves from nearby objects and the ground are suppressed as much aspossible. An anechoic chamber is an example of a free space rangemeasurement location.

CATR is a facility that may be used to provide testing of antennasystems at frequencies where obtaining far-field spacing to the testingdevice may be difficult using traditional free space testing methods. Ina CATR facility, a reflector is used to reflect the waves.

Antenna Reference Point (ARP) is a point located somewhere in theinterface between the radio and the antenna of a base station. ARP isused as a reference in measurements and testing, and various parametersmay be measured relative to the ARP. In AAS base station products, theaccess to the ARP will be limited or it will not be available. Hence,there will be no possibility to carry out conducted measurements foundin conformance test requirements included in traditional specifications(e.g. TS 25.141, TS 36.141, TS 37.141 and TS 37.145-1). Also, all RadioFrequency (RF) testing at Research & Development (R&D) level is todaydone conducted at the ARP. For high frequencies, Over The Air (OTA)testing may be the only way of verifying RF characteristics, such asradiated transmit power (TS 37.145-2) and radiated unwanted emission (tobe included in specifications).

OTA, which is an abbreviation for Over The Air, is a technology fortransmitting radio signals over the air, as distinct from cable or wiretransmission. Over The Air, is an interface that will be used to specifyand verify highly integrated products where there possibly will be noARP available and where the relevant performance need to be defined OTA,as opposed to for traditional radio base stations where performance isspecified and verified in a conducted interface like ARP.

In the Third Generation Partnership Project (3GPP) Release-13 version ofTS 37.145, a limited number of OTA requirements have been introduced(radiated transmit power and OTA sensitivity). There is an ambition todevelop a specification in 3GPP with all RF characteristics defined inthe radiated domain. This means that RF parameters needs to be tested innormal environmental conditions and some requirements are defined inextreme environmental conditions. Specific parameters, such as radiatedtransmit power, radiated unwanted emission, OTA sensitivity andfrequency stability that today are measured using cable, will have to bemeasured OTA. When conducting OTA testing, absolute radiated power willcorrespond to Equivalent Isotropic Radiated Power (EIRP) and absolutereceived power will correspond to Equivalent Isotropic Sensitivity(EIS). Assuming a “black-box” approach without any knowledge about thetest object implementation these two parameters will be verified in somesort of far field antenna test range, with validated measurementuncertainty assessment in normal condition environment

Also, there are regulatory requirements and/or specific customerrequirements asking for that radiated transmit power, carrier frequencystability etc. should be verified OTA in extreme operating conditions.For example a normal operating condition has room temperature and novibrations, and an extreme operating condition may have high or lowtemperature and substantial vibrations. The conditions applicable fornormal operating condition and extreme operating conditions are definedby 3GPP, and will be described later.

Based on R&D quality assurance and customer requirement, the scope ofextreme conditions could extend to also include vibration testing of RFcharacteristics. For receiver sensitivity there is no regulatoryrequirement to measure during extreme conditions, but it can be expectedthat customers will request such information.

The challenge with measuring absolute EIRP and absolute EIS OTA underextreme conditions is that EIRP and EIS are defined in the far-fieldregion. The distance to the far-field region is determined of thephysical size of the test object antenna aperture and the operatingfrequency. It is common that the far-field distance becomes very large,requiring large antenna test facilities. Also, relevant for all types ofantenna test ranges is that they consist of high-precision mechanicalequipment (such as positioners, reflectors, reference antennas, testrange antennas) that are not designed for operation in large temperatureranges. Also, if the equipment could operate in extreme temperaturecondition, the amount of energy needed to cycle the test range would beenormous. Neither can it be made to vibrate according to what isrequired according to the environmental requirements.

To establish specifications with all RF requirements defined in theradiated domain, would put an impossible task on OTA test facilityvendors to handle extreme conditions requirements.

SUMMARY

An objective of embodiments herein is therefore to obviate at least oneof the above disadvantages and to provide improved testing of acommunication device.

According to a first aspect, the object is achieved by a methodperformed by a testing device for enabling testing of a communicationnode. The testing device measures a test parameter associated with RFcharacteristics of the communication node when it is located at a testlocation during a first condition. The communication node is configuredwith a node setting during the measurement in the first condition. Thetesting device measures the test parameter associated with the RFcharacteristics of the communication node when it is located at the testlocation during a second condition. The communication node is configuredwith the same node setting in the second condition as in the firstcondition. The testing device checks whether a result parameterassociated with the test parameter measured during the first and secondcondition fulfills the requirement.

According to a second aspect, the object is achieved by a testing devicefor enabling testing of a communication node. The testing device isconfigured to measure a test parameter associated with RFcharacteristics of the communication node when it is located at a testlocation during a first condition. The communication node is configuredwith a node setting during the measurement in the first condition. Thetesting device is further configured to measure the test parameterassociated with the RF characteristics of the communication node when itis located at the test location during a second condition. Thecommunication node is configured with the same node setting in thesecond condition as in the first condition. The testing device isconfigured to check whether a result parameter associated with the testparameter measured during the first and second condition fulfills therequirement.

Since the test parameters are measured in the test location during afirst and second condition, there is no need for access to e.g. any ARP,and testing of a communication device is improved.

Embodiments herein afford many advantages, of which a non-exhaustivelist of examples follows:

The embodiments herein make it possible to perform OTA testing forextreme condition of RF characteristics, such as radiated transmitpower, OTA sensitivity and radiated unwanted emission. Instead of usinglarge far-field test facilities in extreme condition, the embodimentsherein use a small test box, where the couples signal is measurerelative a known signal measure in normal condition (room temperatureand no vibrations).

The embodiments herein use the fact that absolute values does not haveto be measured during extreme conditions to verify EIRP, EIS andfrequency stability under extreme conditions. Instead a differentialmeasurement approach is used for EIRP and EIS. For example, for EIRP andEIS, the impact of extreme conditions on the test object is measured.The difference may be added to an absolute measurement that has beendone in a far field test range or a CATR. Note that frequency stabilityis measured in absolute figures, both in normal and extreme conditions.

To minimize the risk for errors, the communication node may carry amemory where reference data is stored. The reference data may be used toextract RF characteristics in an extreme condition. The data is acomposite set of measurement results and associated configurationparameters.

The embodiments herein are not limited to the features and advantagesmentioned above. A person skilled in the art will recognize additionalfeatures and advantages upon reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will now be further described in more detail inthe following detailed description by reference to the appended drawingsillustrating the embodiments and in which:

FIG. 1 is a schematic block diagram illustrating an example of a system.

FIG. 2 is a flow chart illustrating an example method using EIRP & EIS.

FIG. 3 is a flow chart illustrating an example method using frequencystability and TAE.

FIG. 4 is a schematic block diagram illustrating an example of a testenvironment.

FIG. 5 is a schematic block diagram illustrating an example of a testenvironment.

FIG. 6a is a schematic block diagram illustrating a top view of avibrator.

FIG. 6b is a schematic block diagram illustrating a side view of avibrator.

FIG. 7 is a flow chart illustrating an example of a method.

FIG. 8 is a schematic block diagram illustrating embodiments of atesting device.

The drawings are not necessarily to scale and the dimensions of certainfeatures may have been exaggerated for the sake of clarity. Emphasis isinstead placed upon illustrating the principle of the embodimentsherein.

DETAILED DESCRIPTION

FIG. 1 illustrates an example of a testing device 101 which may executetesting of a communication node 103. For example, the testing device 101may test whether the communication node 103 is capable of operatingduring extreme environmental conditions by measuring test parameters andpossibly also reference parameters.

The testing device 101 is connected to the communication node 103 via awire. The testing device 101 may be for example a computer, anothercommunication node 103 etc. The testing is done by measuring parameterssuch as Radio Frequency (RF) characteristic parameters associated withthe communication node 103.

The communication node 103 to be teste may comprise base band equipment,radio equipment and at least one antenna. The communication node 103which is subject to the testing may be an AAS base station (with asingle or multiple enclosure solution). Recall from above that an AASbase station is a base station where at least the antenna and the radioequipment are co-located. In an AAS base station with a single enclosuresolution, the baseband equipment and the radio equipment are located inone capsuling. This means that the communication node 103 which istested is constituted by the baseband equipment, the radio equipment andthe antenna. In an AAS base station with a multiple enclosure solution,the communication node 103 which is tested is constituted by the radioequipment and the antenna. In this case, the baseband equipment isseparated from the radio equipment (there may be e.g. an opticalconnection between the baseband and radio equipment), and is not part ofthe object which is under test. The communication node 103 may also bereferred to as a test base station or an Antenna Under Test (AUT),Device Under Test (DUT) etc.

The communication node 103 has a certain node setting during thetesting. The same node setting is applied to the communication node 103during testing in any location and in any condition. Informationregarding the node setting is stored in the communication node 103. Inaddition, the information regarding the node setting may be stored in anexternal memory, the testing device 101, in a cloud memory, or any othersuitable memory which is accessible (using wireless or wiredcommunication) by the communication node 103 and the testing device 101.The node setting may be band configuration, output power etc. of thecommunication node 103 during the measurement of the parameters.

During the test, the communication node 103 may be located in referencelocation (not shown) or in a test location 105.

The test location 105 may be adapted to have different conditions, i.e.a first condition and a second condition. The first condition isdifferent from the second condition with regards to e.g. temperature andvibration. The first condition may be referred to as a normal operatingcondition and the second condition may be referred to as an extremeoperating condition. The terms normal test environment and extreme testenvironment, normal condition and extreme condition may also be usedwhen referring to the first and second conditions.

A normal operating condition may be described as a condition with roomtemperature and without substantial vibrations. In a normal operatingcondition, the communication node 103 operates correctly and there is alow risk for component failure. An extreme operating condition may bedescribed as a condition with a high or low temperature (high comparedto the room temperature, and low compared to the room temperature)and/or with vibrations. The extreme operating condition may have forexample a maximum extreme temperature, a minimum extreme temperature, amaximum vibration etc. in which the communication node 103 is capable ofoperating. If the communication node 103 is subject to even higher orlower temperatures or vibrations, it is a risk that it will not operatecorrectly and there is a risk for component failure.

In a normal condition, the test may be performed within certain minimumand maximum limits. Such limits may be defined by the manufacturer ofthe communication node 103.

For example, Annex B2 of Release 13 of 3GPP TS 37.141 V13.2.0 (2016March) defines the conditions of a normal test environment as a testbeing performed within the minimum and maximum limits stated in Table 1below:

TABLE 1 Condition Minimum Maximum Barometric pressure 86 kPa 106 kPaTemperature 15° C.   30° C.   Relative Humidity 20% 85% Power supplyNominal, as declared by the manufacturer Vibration Negligible

In an extreme test environment, the communication node 103 is subject toat least one extreme parameter such as for example extreme temperature(minimum or maximum temperature for the communication node 103 which isdefined by the manufacturer), vibration (the test may be performed whilethe communication node 103 is subjected to a vibration sequence asdefined by the manufacturer) and power supply (upper and lower voltagelimit, as defined by the manufacturer).

In some embodiments, there may be two test locations 105, where eachtest location has a specific condition. For example a first testlocation may have a first condition and a second test location may havea second condition. In order to test the communication node 105 indifferent conditions, the communication node 105 needs to be moved fromone location to the other. Note that only one test location 105 isillustrated in FIG. 1 for the sake of simplicity.

The test location 105 may be a closed space, typically an indoorlocation. The test location 105 may be for example a box or a chamber,e.g. a RF anechoic chamber. An anechoic chamber is a chamber or boxdesigned to completely absorb reflections of sound or electromagneticwaves. An anechoic chamber is also insulated from exterior sources ofnoise. Measurements obtained in the test location 105 may be referred toas test parameters or relative test values.

The reference location may be a far field test range or a CATR, and hasa condition which is substantially similar to one of the conditions inthe test location 105, e.g. a first condition. Measurements obtained inthe reference location may be referred to as reference parameters orabsolute reference values.

An absolute value or number is a real or precise number. A relativevalue is dependent on or compared with another value. For example, arelative value is dependent on or compared with an absolute value.

A reference node 108 may be also used in the testing in order totransmit radio waves to the communication node 103 OTA and to receiveradio waves transmitted from the communication node 103 OTA. Thereference node 108 could be moved to scan the electrical field over thewhole antenna aperture of the communication node 103. The testing device101 may be connected to the reference node 108 via a wire. The referencenode 108 may be located in the reference location or in the testlocation 105, or in both. The reference node 108 may also be referred toas a probe antenna (when located in the test location 105) and as a testrange antenna (when located in the reference location).

Radio frequency characteristics of a communication node 103 such as anAAS base station can be divided into following categories based onfigure of merit:

-   -   1. Amplitude (or power) level based characteristics, such as        output power (Equivalent Isotopically Radiated Power (EIRP),        unwanted emission and sensitivity (Equivalent Isotropic        Sensitivity (EIS)).    -   2. Frequency or timing based characteristics, such absolute        carrier frequency and Timing Alignment Error (TAE).

EIRP is a RF characteristic parameter of a communication node 103 whichmay be described as the specified or measured radiated or transmittedpower in a single direction. Another way of describing EIRP is theamount of power a perfectly isotropic antenna would need to radiate toachieve the measured value. EIS is another such RF characteristicparameter which provides the measured sensitivity in a single directionfor the communication node 103. TAE is a RF characteristic for acommunication node 103 which may be defined as the largest timingdifference between any two signals from antennas at the transmittingantenna ports. The absolute carrier frequency should be within certainfrequency boundaries. If it is, then it can be said that there isfrequency stability.

In one example (explained in more detail with reference to FIG. 2later), the principle that RF characteristics for a communication node103 can be verified in environmental conditions can be done by splittingup the requirement and testing in two cases:

-   -   1. Absolute measurement of radiated RF characteristics in normal        temperature condition.    -   2. Relative measurement of radiated RF characteristics in        extreme temperature condition.

The embodiments herein allow usage of antenna test ranges operating inroom temperature condition (e.g. direct far-field, Compact Antenna TestRange (CATR) or near-field scanner based approaches). The absolutemeasurement values in a normal condition may be used as a reference forthe relative measurement conducted in extreme temperature condition. Theextreme temperate condition measurement requires a new type of OTA testapproach, where the communication node 103 is put in a rather smallshielded anechoic chamber, where the temperature can easily becontrolled. Also extreme conditions for vibration can be managed in thistype of test location 105.

In the test location 105, the field strength in the near-field close tothe communication node 103 to be tested is measured for relevantpositions over the antenna aperture comprised in the communication node103. This type of near-field measurement will not give any absolutemeasurement values, instead it can be used to measure relative deviationto the absolute measured value in room temperature.

The measurement procedure can briefly be described as:

-   -   a. Measure absolute reference value in normal condition (room        temperature) using measurement facility A (reference location).    -   b. Measure near-field coupled value in normal condition (room        temperature) using measurement facility B (test location). This        test point associates the measure EIRP/EIS level measured in (a)        with the power measured in the near-field using measurement        facility B (test location 105).    -   c. Measure near-field coupled value in extreme condition        (maximum temperature) using measurement facility B (test        location 105).    -   d. Measure near-field coupled value in extreme condition        (minimum temperature) using measurement facility B (test        location 105).    -   e. Measure near-field coupled value in extreme condition (room        temperature and vibration) using measurement facility B (test        location 105)    -   f. Measure near-field coupled value during vibration in normal        condition (room temperature) using measurement facility B (test        location 105).

This approach of handling OTA testing in extreme condition requires thecommunication node 103 to be tested to be configured exactly the samewhen RF characteristics are tested in facility A and B, i.e. in thereference location and the test location.

First the communication node 103 is tested according to OTA requirements(such as radiated transmit power and OTA sensitivity). This test isconducted in test facility A (reference location).

The communication node 103 is thereafter directly moved to a testfacility B (test location) 105), which can be described as a shieldedanechoic box. As mentioned above, inside the box 105 a reference antenna108 is situated that can either transmit or receive power OTA. Thereference antenna 108 could be moved to scan the electrical field overthe whole antenna aperture of the communication node 103. Theenvironment with respect to temperature and vibration can be controlledduring the testing.

In a shielded anechoic chamber 105, the temperate can be controlled byeither changing the air using an external temperate chamber andcirculating fan or placing the test location 105 with the communicationnode 103 in a large temperate chamber. The approach to achievetemperature balance is selected based on access to specific testequipment.

For an EIRP test, the communication node 103 is then activated intransmitter mode during normal conditions. The power received by themeasurement probe 108 in facility B (i.e. the test location 105) isdetected during normal conditions and stored. The measurement may bedone for two orthogonal polarizations. Measurements are thereaftercarried out under extreme conditions, e.g. temperature and vibration,and received power in the reference antenna 108 is detected. Thedifferential between measured values during normal and extremeconditions may be calculated and translated to EIRP under extremeconditions by adding the differential to measured values in the testfacility A (e.g. CATR, reference location).

Frequency stability and Time Alignment Error (TAE) under extremeconditions may be measured by only using the test location 105 describedas facility B. First under normal conditions and thereafter applyingextreme conditions. In other words, it is not necessary to measure thefrequency stability and TAE in the reference location and to obtainabsolute measurement values. This is described in more detail withreference to FIG. 3 below.

Since environmental conditions testing using this approach requires twodifferent OTA test facilities; one for normal condition and one forextreme condition, the test object (AKA communication node 103) may havefunctionality to store measurement data associated to normal condition.The stored data is then used as reference when the communication node103 is subject to the extreme testing. The data may comprise at leastone of absolute measurement values and associated configurationparameters. By putting a memory in the communication node 103, itminimizes the risk to use the wrong reference when RF characteristicsfor extreme condition are calculated. The reference data relevant fornormal condition is stored when RF characteristics is done in testfacility A (reference location).

Two example methods for enabling testing of a communication node willnow be described with reference to FIG. 2 and FIG. 3. FIG. 2 is a flowchart illustrating an example of the method where the parameters to beused in the testing are EIRP and EIS. FIG. 3 is a flow chartillustrating another example of the method where the parameters to beused in the testing are frequency stability and TAE. In other words, thedifference between FIGS. 2 and 3 is the RF parameters that are measuredduring the testing.

Starting with FIG. 2. FIG. 2 illustrates a process for OTA EIRP & EISverification under extreme conditions. In FIG. 2, the first condition isexemplified with a normal condition and the second condition isexemplified with an extreme condition. The example method illustrated inFIG. 2 comprises at least some of the following steps, which steps maybe performed in any suitable order than described below:

Step 201

The communication node 101 to be tested is located at a far field testrange or a CATR in step 201. The far field test range or CATR has anormal condition. The testing device 101 measures the EIRP and EISvalues associated with the communication node 103 in the far field testrange or the CATR under the normal condition. The measured EIRP and EISvalues are saved, for example in a matrix X. The matrix X may have anydimension n×n, where n is any positive integer.

X=[EIRP _(x) EIS _(x)]

The testing device 101 enables the node settings such as bandconfiguration, output power etc. to be stored in the communication node103 (e.g. a memory of the communication node 103), for use in allfollowing measurements.

The measurement performed in step 201 may be seen as a referencemeasurement obtaining reference parameters which are absolute values tobe used in comparison with other measurement values, i.e. relativevalues, obtained in the steps below. Thus, the far field test range orthe CATR where the communication node 103 is located during themeasurement in step 201 may be seen as a reference location.

In the far field test range or a CATR, there may be a reference antenna108. The reference antenna 108 may be referred to as a test rangeantenna in the far field test range or CATR.

The reference parameters EIRP and EIS measured in the field test rangeor CATR are OTA measurements obtained using the reference antenna 108.

Step 202

The testing device 101 checks whether the measured EIRP and EIS valuesfulfils a requirement. Using other words, the testing device 101 checksif the values in matrix X (From step 201) are within the limits of therequirement matrix R. The requirement matrix R may have any dimensionm×m, where m is any positive integer. The requirement may be defined bythe manufacturer of the communication node 103.

If the values do not fulfil the requirement, the method proceeds to step203 (indicated with “no” in FIG. 2). If the values fulfil therequirement, the method proceeds to step 204 (indicated with “yes” inFIG. 2).

Requirement information (e.g. the matrix R) may be stored in at leastone of the communication node 103, the testing device 101, an externalmemory, in a cloud memory etc.

The requirement may be for example as described in Release 13 of 3GPP TS37.105 V13.0.0 (2016 March).

Step 203

This step is performed if the measured EIRP and EIS do not fulfil therequirement checked in step 202. Since the measured EIRP and EIS underthe normal requirement did not fulfil the requirement, the testingdevice 101 determines that the communication node 103 fails theverification of operation during normal condition, i.e. thecommunication node 103 is not capable of operating during normalconditions.

Step 204

This step is performed if the measured EIRP and EIS fulfil therequirement checked in step 202. The communication node 103 is moved toa test location, and the test location has a normal operating condition.The testing device 101 measures the EIRP & EIS values associated withthe communication node 103 in the test location 105 under normalconditions. The EIRP is measured when the communication node 103transmits radio waves to be received by the reference node 108, and theEIS is measured when the communication node 103 receives radio wavestransmitted by the reference node 108. The node settings saved incommunication node memory is used, i.e. the communication node 103 hasthe same settings in both steps 201 and 204. The EIRP and EIS measuredin step 204 are saved in matrix Y. Matrix Y may have any dimension p×p,where p is a positive integer.

Y=[EIRP _(Y) EIS _(Y)]

Step 205

This step is performed if the measured EIRP and EIS fulfil therequirement checked in step 202. This step may be performed after step204, or between step 203 and 204. The communication node 103 is stilllocated at the test location, and the test location now has an extremeoperating condition. The testing device 101 measures the EIRP and EISvalues associated with the communication node 103 in the test locationunder extreme conditions (high & low temperature or vibrations). Asabove, the EIRP is measured when the communication node 103 transmitsradio waves to be received by the reference node 108, and the EIS ismeasured when the communication node 103 receives radio wavestransmitted by the reference node 108. The node settings saved incommunication node memory is applied to the communication node 103during the testing. The measured EIRP and EIS values may be saved inmatrix Z. The matrix Z may be of any dimension d×d, where d is apositive integer.

Z=[EIRP _(Z) EIS _(Z)]

Step 206

The testing device 101 may derive the difference between the EIRP andEIS measured in steps 204 and 205. The difference may be added to thevalues measured in step 201. This may be described as a comparison ofthe reference measurement in step 201 with the test measurements insteps 204 and 205. So, for the EIRP and EIS measured in steps 204 and205, the difference between the values in matrix Y and Z are added tothe values in matrix X. The sum may be stored in matrix S, and matrix Smay be of any dimension q×q, where q is a positive integer:

S=X+(Z−Y)

The matrix S may be referred to as a result parameter, and the matrix Rmay be referred to as a requirement parameter or a requirement.

Step 207

The testing device 101 checks whether the values in matrix S fulfils therequirement (the same requirement as in step 202), i.e. if the matrix Sis within the limits of the requirement matrix R. The requirement matrixR may be defined by the manufacturer of the communication node 103.

If the values do not fulfil the requirement, the method proceeds to step208 (indicated with “no” in FIG. 2). If the values fulfil therequirement, the method proceeds to step 209 (indicated with “yes” inFIG. 2).

Step 208

This step is performed if the matrix S does not fulfil the requirementchecked in step 207. Since the matrix S did not fulfil the requirement,the testing device 101 determines that the communication node 103 failsthe verification of operation during an extreme condition, i.e. thecommunication node 103 is not capable of operating during extremeconditions.

Step 209

This step is performed if the measured EIRP and EIS fulfil therequirement checked in step 207. Since the matrix S fulfils therequirement, the testing device 101 determines that the communicationnode 103 passes the verification of operation during an extremecondition, i.e. the communication node 103 is capable of operatingduring extreme conditions.

Information indicating the parameters measured in FIG. 2, requirement(e.g. requirement matrix R), the calculated difference, the resultparameter (e.g. matrix S), the matrixes X, Y and Z may be stored in anysuitable memory, e.g. a memory comprised in at least one of thecommunication node 103, testing device 101, external memory, cloudmemory etc.

Now turning to FIG. 3. FIG. 3 illustrates a process for OTA frequency &TAE verification under extreme conditions. In FIG. 3, the firstcondition is exemplified with a normal condition and the secondcondition is exemplified with an extreme condition. As mentioned above,one difference between FIGS. 2 and 3 is the parameters which aremeasured. Other differences are that in FIG. 3, there is no measurementperformed at a reference location, i.e. at a far field test range/CATR,and that the testing device 101 does not calculate any differencebetween the measurements. The communication node 103 is only tested atthe test location in FIG. 3. The example method illustrated in FIG. 3comprises at least some of the following steps, which steps may beperformed in any suitable order than described below:

Step 301

This step corresponds to step 204 in FIG. 2, but different RF parametersare measured. The testing device 101 measures the communication node'sfrequency stability (f) and TAE values of the communication node 103 inthe test location under normal conditions. The frequency and TAE valuesmeasured in step 301 may be saved in matrix Y. Matrix Y may have anydimension p×p, where p is a positive integer.

Y=[f _(Y) TAE _(Y)]

The communication node settings such as band configuration, output poweretc. may be stored in the communication node memory, for use in allfollowing measurements.

Step 302

The testing device 101 checks whether the measured frequency stabilityand TAE values fulfils a requirement. Using other words, the testingdevice 101 checks if the values in matrix Y (From step 301) are withinthe limits of the requirement matrix R. The requirement matrix R mayhave any dimension m×m, where m is any positive integer. The requirementmay be defined by the manufacturer of the communication node 103.

If the values do not fulfil the requirement, the method proceeds to step303 (indicated with “no” in FIG. 3). If the values fulfil therequirement, the method proceeds to step 304 (indicated with “yes” inFIG. 3).

The requirement may be for example as described in Release 13 of 3GPP TS37.105 V13.0.0 (2016 March).

Step 303

This step is performed if the measured frequency and TAE values do notfulfil the requirement checked in step 302. Since the measured frequencyand TAE values under the normal requirement did not fulfil therequirement, the testing device 101 determines that the communicationnode 103 fails the verification of operation during normal condition,i.e. the communication node 103 is not capable of operating duringnormal conditions.

Step 304

This step corresponds to step 205 in FIG. 2, but different RF parametersare measured. This step is performed if the measured frequency and TAEvalues fulfil the requirement checked in step 302. The communicationnode 103 is still located at the test location, and the test locationnow has an extreme operating condition. The testing device 101 measuresthe frequency and TAE values of the communication node 103 in the testlocation under extreme conditions (high & low temperature orvibrations). The node settings saved in communication node memory isapplied to the communication node 103 during the testing. The measuredfrequency and TAE values may be saved in matrix Z. The matrix Z may beof any dimension d×d, where d is a positive integer.

Z=[f _(Z) TAE _(Z)]

Frequency stability is measured in absolute figures, both in normal andextreme conditions.

Step 305

The testing device 101 may store frequency stability & TAE measurementvalues, saved in matrix Y and Z, in matrix S:

S=[YZ].

Step 306

This step corresponds to step 207 in FIG. 2. The testing device 101checks whether the values in matrix S fulfils the requirement (the samerequirement as in step 302), i.e. if the matrix S is within the limitsof the requirement matrix R. The requirement matrix R may be defined bythe manufacturer of the communication node 103.

If the values do not fulfil the requirement, the method proceeds to step307 (indicated with “no” in FIG. 3). If the values fulfil therequirement, the method proceeds to step 308 (indicated with “yes” inFIG. 3).

As mentioned earlier, there is no need to calculate any difference inFIG. 3 (as in FIG. 2). The Y and Z values (stored in S) can be compareddirectly towards the requirement in matrix S.

Note that the matrixes X, Y, Z, R and S may be of the same or differentdimension.

Step 307

This step corresponds to step 208 in FIG. 2. This step is performed ifthe matrix S does not fulfil the requirement checked in step 306. Sincethe matrix S did not fulfil the requirement, the testing device 101determines that the communication node 103 fails the verification ofoperation during an extreme condition, i.e. the communication node 103is not capable of operating during extreme conditions.

Step 308

This step corresponds to step 209 in FIG. 2. This step is performed ifthe measured frequency and TAE fulfil the requirement checked in step306. Since the matrix S fulfils the requirement, the testing device 101determines that the communication node 103 passes the verification ofoperation during an extreme condition, i.e. the communication node 103is capable of operating during extreme conditions.

Information indicating the parameters measured in FIG. 3, requirement(e.g. requirement matrix R), the result parameter (e.g. matrix S), thematrixes X, Y and Z may be stored in any suitable memory, e.g. a memorycomprised in at least one of the communication node 103, testing device101, external memory, cloud memory etc.

FIG. 4 is a schematic block diagram illustrating an example of thetesting environment. In FIG. 4, the test location 105 is exemplifiedwith an anechoic chamber. The communication node 103 is placed insidethe anechoic chamber 105. An air flow 401 is forced to pass through theanechoic chamber 105 in order to control the temperature. The bendedarrow below the test location 105 indicates that the air flow 401 leavesthe test location 105 after having passed the communication node 103. Asmentioned above, the temperate can be controlled by either changing theair using an external temperate chamber and circulating fan or placingthe test location 105 with communication node 105 in a large temperatechamber. The approach to achieve temperature balance may be selectedbased on access to specific test equipment.

As mentioned earlier, the different conditions in which thecommunication node 103 is tested have different temperature, vibration,power supply etc. In order to provide vibration of the communicationnode 103 in the second condition (e.g. extreme condition), a vibratormay be used. FIG. 5 is a schematic block diagram illustrating an examplewhere the communication node 103 is placed inside the test location 105,e.g. an anechoic chamber. The test location 105 is placed above avibrator and isolated from the moving parts. The communication node 103is connected to the vertical moving inner cylinder 503 via a mechanicalfixture 504. FIG. 5 illustrates an example with a vertical vibrator, buta horizontal vibrator can also be used. In FIG. 5, the test location 105is exemplified as a box with support legs 508. When vibration is appliedto the communication node 103, the cylinder 503, the communication node103 and the mechanical fixture 504 are the parts which are moving, i.e.vibrating. The cylinder 503 and a base unit 505 may be seen as one unit,i.e. the vibrator. The base unit 505 may be a unit which is fixedlymounted and the cylinder 503 is the moving part. The mechanical fixture504 is a unit for connecting the cylinder 503 and the communication node103.

FIG. 6a is a schematic block diagram illustrating a top view of vibratorwith the outer fixed cylinder 505 and the inner vertically vibratingcylinder 503. FIG. 6b is a schematic block diagram illustrating a sideview of the vibrator with the outer fixed cylinder 505 and innervertically vibrating cylinder 503.

The method described above will now be described using FIG. 7. Themethod performed by the testing device 101 comprises at least some ofthe following steps, which steps may be performed in any suitable orderthan described below:

Step 700

This step corresponds to step 201 in FIG. 2. The testing device 101 maymeasure a reference parameter associated with the RF characteristics ofthe communication node 103 when the communication node 103 is at areference location during the first condition. The communication node103 is configured with the same node setting during measurement of thereference parameter as during the first and second conditions.

The communication node 103 may be located in a far field test range orCATR when being located at the reference location.

The first condition may be a normal operating condition of thecommunication node 103.

The communication node 103 may be an AAS base station.

Step 701

This step corresponds to step 202 in FIG. 2. The testing device 101 maycheck whether the reference parameter measured at the reference locationduring the first condition fulfills a requirement. The test parameter ismeasured at the test location 105 during the first condition when thetest parameter fulfills the requirement.

Step 702

This step corresponds to step 203 in FIG. 2. When the referenceparameter does not fulfil the requirement (indicated with “no” in FIG.7), the testing device 101 verifies that the communication node 103 isnot capable of operating during the first condition.

Step 703

This step corresponds to step 204 in FIG. 2. When the referenceparameter fulfils the requirement (indicated with “yes” in FIG. 7), thetesting device 101 verifies that the communication node 103 is capableof operating during the first condition.

Step 704

This step corresponds to step 204 in FIG. 2, step 301 in FIG. 3. Thetesting device 101 measures a test parameter associated with RFcharacteristics of the communication node 103 when it is located at atest location 105 during the first condition. The communication node 103is configured with a node setting during the measurement in the firstcondition.

The test parameter may be at least one of: Equivalent Isotropic RadiatedPower (EIRP), Equivalent Isotropic Sensitivity (EIS), Timing AlignmentError (TAE) and frequency stability.

The test location 105 may be a radio frequency anechoic chamber.

Step 705

This step corresponds to step 302 in FIG. 3. The testing device 101checks whether the test parameter measured during the first conditionfulfills a requirement.

Step 706

This step corresponds to step 303 in FIG. 3. When the test parameterduring the first condition does not fulfil the requirement (indicatedwith “no” in FIG. 7), the testing device 101 may verify that thecommunication node 103 is not capable of operating during the firstcondition

Step 707

This step corresponds to step 304 in FIG. 3. When the test parameterduring the first condition fulfils the requirement (indicated with “yes”in FIG. 7), the testing device 101 may verify that communication node103 is capable of operating in the first condition.

Step 708

This step corresponds to step 205 in FIG. 2 and step 304 in FIG. 3. Thetesting device 101 measures the test parameter associated with the RFcharacteristics of the communication node 103 when it is located at thetest location 105 during a second condition. The communication node 103is configured with the same node setting in the second condition as inthe first condition.

The second condition may be an extreme operating condition of thecommunication node 103.

Step 709

This step corresponds to step 206 in FIG. 2. The testing device 101 maycalculate a difference between the test parameter measured in the firstand second conditions. The result parameter is a sum of the referenceparameter and the calculated difference.

The result parameter may comprise the test parameter measured during thefirst and second conditions.

Step 710

This step corresponds to step 207 in FIG. 2 and step 306 in FIG. 3. Thetesting device 101 checks whether the result parameter associated withthe test parameter measured during the first and second conditionfulfils the requirement.

Step 711

This step corresponds to step 209 in FIG. 2 and step 308 in FIG. 3. Whenthe result parameter fulfils the requirement, the testing device 101 mayverify that the communication node 103 is capable of operating duringthe second condition.

Step 712

This step corresponds to step 208 in FIG. 2 and step 308 in FIG. 3. Whenthe result parameter does not fulfil the requirement, the testing device101 may verify that the communication node 103 is not capable ofoperating during the second condition.

The node setting, the test parameter measured during the first andsecond conditions may be stored in at least one of: the communicationnode 103, the testing device 101 and an external memory.

The reference parameter and the test parameters in the first and secondconditions may be OTA measurements using a reference antenna 108.

To perform the method steps shown in FIG. 7 for enabling testing of acommunication node 103, the testing device 101 may comprise anarrangement as shown in FIG. 8. To perform the method steps shown inFIG. 7 for enabling testing of a communication node 103, the testingdevice 101 is configured to, e.g. by means of a measuring module 801,measure a test parameter associated with RF characteristics of thecommunication node 103 when it is located at a test location 105 duringa first condition. The communication node 103 is configured with a nodesetting during the measurement in the first condition. The testparameter may be at least one of: EIRP, EIS, TAE and frequencystability.

The testing device 101 is further configured to, e.g. by means of themeasuring module 801, measure the test parameter associated with the RFcharacteristics of the communication node 103 when it is located at thetest location 105 during a second condition. The communication node 103is configured with the same node setting in the second condition as inthe first condition.

The testing device 101 is configured to, e.g. by means of a checkingmodule 803, check whether a result parameter associated with the testparameter measured during the first and second condition fulfills therequirement.

The testing device 101 may be configured to, e.g. by means of themeasuring module 801, measure a reference parameter associated with theRF characteristics of the communication node 103 when the communicationnode 103 when it is at a reference location during the first condition.The communication node 103 may be configured with the same node settingduring measurement of the reference parameter as during the first andsecond conditions. The communication node 103 may be located in a farfield test range or Compact Antenna Test Range (CATR), when beinglocated at the reference location. The reference parameter may be atleast one of: EIRP and EIS.

The testing device 101 may be configured to, e.g. by means of thechecking module 803, check whether the reference parameter measured atthe reference location during the first condition fulfills arequirement.

The testing device 101 may be configured to, e.g. by means of acalculating module 805, calculate a difference between the testparameter measured in the first and second conditions. The resultparameter may be a sum of the reference parameter and the calculateddifference. The result parameter may comprise the test parametermeasured during the first and second conditions.

The testing device 101 may be configured to, e.g. by means of averifying module 808, when the result parameter fulfils the requirement,verify that the communication node 103 is capable of operating duringthe second condition.

The testing device 101 may be configured to, e.g. by means of theverifying module 808, when the result parameter does not fulfil therequirement, verify that the communication node 103 is not capable ofoperating during the second condition.

The testing device 101 may be configured to, e.g. by means of thechecking module 803, check whether the test parameter measured duringthe first condition fulfills a requirement.

The testing device 101 may be configured to, e.g. by means of theverifying module 808, when the test parameter during the first conditiondoes not fulfil the requirement, verify that the communication node 103is not capable of operating during the first condition.

The node setting, the test parameter measured during the first andsecond conditions may be stored in at least one of: the communicationnode 103, the testing device 101 and an external memory.

The first condition may be a normal operating condition of thecommunication node 103 and the second condition may be an extremeoperating condition of the communication node 103. The first conditionmay be a normal environmental condition at the reference location andthe test location 105 and the second condition may be an extremeenvironmental condition at the test location 105.

The communication node 103 may be an AAS base station.

The reference parameter and the test parameters in the first and secondconditions may be OTA measurements using a reference antenna 108.

The test location 105 may be a radio frequency anechoic chamber

The testing device 101 may comprises a processor 810 and a memory 813.The memory 813 comprises instructions executable by the processor 810.

The memory 813 may comprise one or more memory units. The memory 813 maybe arranged to be used to store data, received data streams, power levelmeasurements, threshold values, time periods, configurations,schedulings, test parameters, reference parameters, result parameter,matrices, requirement information, node settings, first conditioninformation, second condition information and applications to performthe methods herein when being executed in the testing device 101.

The present mechanism for enabling testing of a communication node 103may be implemented through one or more processors, such as the processor810 in the testing device 101 depicted in FIG. 8, together with computerprogram code for performing the functions of the embodiments herein. Theprocessor may be for example a Digital Signal Processor (DSP),Application Specific Integrated Circuit (ASIC) processor,Field-programmable gate array (FPGA) processor or microprocessor. Theprogram code mentioned above may also be provided as a computer programproduct, for instance in the form of a data carrier carrying computerprogram code for performing the embodiments herein when being loadedinto the testing device 101. One such carrier may be in the form of a CDROM disc. It is however feasible with other data carriers such as amemory stick. The computer program code can furthermore be provided aspure program code on a server and downloaded to the testing device 101.

A computer program may comprise instructions which, when executed on atleast one processor, cause the at least one processor to carry out atleast some of the method steps in FIGS. 2, 3 and 7. A carrier maycomprise the computer program, and the carrier is one of an electronicsignal, optical signal, radio signal or computer readable storagemedium.

Summarized, the embodiments herein use the difference in result ofmeasurements in normal and extreme conditions of EIRP, EIS, frequencystability and TAE. For EIRP and EIS, normal and extreme measurementvalues can be calibrated towards absolute values by relating measurementresults toward measurements carried out in a far field test range/CATR(i.e. a reference location). To ensure that measurements in extremeconditions are fully compatible with reference measurements in far fieldtest range/CATR, node settings and the measurement values from thereference measurement are stored in a memory in the communication node103 and shall be used to assure that exactly the same settings are usedwhen doing the measurements in extreme conditions.

The embodiments herein are not limited to the above describedembodiments. Various alternatives, modifications and equivalents may beused. Therefore, the above embodiments should not be taken as limitingthe scope of the embodiments, which is defined by the appending claims.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps or components, but does not preclude thepresence or addition of one or more other features, integers, steps,components or groups thereof. It should also be noted that the words “a”or “an” preceding an element do not exclude the presence of a pluralityof such elements.

The term “configured to” used herein may also be referred to as“arranged to”, “adapted to”, “capable of” or “operative to”.

It should also be emphasised that the steps of the methods defined inthe appended claims may, without departing from the embodiments herein,be performed in another order than the order in which they appear in theclaims.

1. A method performed by a testing device for enabling testing of acommunication node, the method comprising: measuring a test parameterassociated with radio frequency (RF) characteristics of thecommunication node when it is the communication node is located at atest location during a first condition, wherein the communication nodeis configured with a node setting during the measurement in the firstcondition; measuring the test parameter associated with the RFcharacteristics of the communication node when the communication node islocated at the test location during a second condition, wherein thecommunication node is configured with the same node setting in thesecond condition as in the first condition; and checking whether aresult parameter associated with the test parameter measured during thefirst and second conditions fulfills a requirement.
 2. The methodaccording to claim 1, further comprising: measuring a referenceparameter associated with the RF characteristics of the communicationnode when the communication node is at a reference location during thefirst condition, wherein the communication node is configured with thesame node setting during measurement of the reference parameter asduring the first and second conditions.
 3. The method according to claim2, further comprising: checking whether the reference parameter measuredat the reference location during the first condition fulfills therequirement.
 4. The method according to claim 2, wherein thecommunication node is located in a far field test range or CompactAntenna Test Range, CATR, when being located at the reference location.5. The method according to claim 1, further comprising: calculating adifference between the test parameter measured in the first and secondconditions, wherein the result parameter is a sum of the referenceparameter and the calculated difference.
 6. The method according toclaim 1, wherein the result parameter comprises the test parametermeasured during the first and second conditions.
 7. The method accordingto claim 1, further comprising: when the result parameter fulfils therequirement, verifying that the communication node is capable ofoperating during the second condition.
 8. The method according to claim1, further comprising: when the result parameter does not fulfil therequirement, verifying that the communication node is not capable ofoperating during the second condition.
 9. The method according to claim1, further comprising checking whether the test parameter measuredduring the first condition fulfills a requirement.
 10. The methodaccording to claim 9, further comprising: when the test parameter duringthe first condition does not fulfil the requirement, verifying that thecommunication node is not capable of operating during the firstcondition.
 11. The method according to claim 1, wherein the nodesetting, the test parameter measured during the first and secondconditions are stored in at least one of: the communication node, thetesting device and an external memory.
 12. The method according to claim1, wherein the test parameter is at least one of: Equivalent IsotropicRadiated Power, Equivalent Isotropic Sensitivity, Timing AlignmentError, and frequency stability.
 13. The method according to claim 1,wherein the first condition is a normal environmental condition and thesecond condition is an extreme environmental condition.
 14. The methodaccording to claim 1, wherein the communication node is an ActiveAntenna System base station.
 15. The method according to claim 1,wherein the test parameters in the first and second conditions are OverThe Air measurements using a reference antenna.
 16. The method accordingto claim 1, wherein the test location is a radio frequency anechoicchamber.
 17. A testing device for enabling testing of a communicationnode, wherein the testing device is configured to: measure a testparameter associated with radio frequency (RF) characteristics of thecommunication node when it is located at a test location during a firstcondition, wherein the communication node is configured with a nodesetting during the measurement in the first condition; measure the testparameter associated with the RF characteristics of the communicationnode when it is located at the test location during a second condition,wherein the communication node is configured with the same node settingin the second condition as in the first condition; and check whether aresult parameter associated with the test parameter measured during thefirst and second condition fulfills the requirement.
 18. The testingdevice according to claim 17, being further configured to: measure areference parameter associated with the RF characteristics of thecommunication node when the communication node when it is at a referencelocation during the first condition, wherein the communication node isconfigured with the same node setting during measurement of thereference parameter as during the first and second conditions.
 19. Thetesting device according to claim 18, being further configured to: checkwhether the reference parameter measured at the reference locationduring the first condition fulfills the requirement.
 20. The testingdevice according to claim 18, wherein the communication node is locatedin a far field test range or Compact Antenna Test Range when beinglocated at the reference location.
 21. The testing device according toclaim 18, being further configured to: calculate a difference betweenthe test parameter measured in the first and second conditions, whereinthe result parameter is a sum of the reference parameter and thecalculated difference.
 22. The testing device according to claim 17,wherein the result parameter comprises the test parameter measuredduring the first and second conditions.
 23. The testing device accordingto claim 17, being further configured to: when the result parameterfulfils the requirement, verify that the communication node is capableof operating during the second condition.
 24. The testing deviceaccording to claim 17, being further configured to: when the resultparameter does not fulfil the requirement, verify that the communicationnode is not capable of operating during the second condition.
 25. Thetesting device according to claim 17, being further configured to: checkwhether the test parameter measured during the first condition fulfillsa requirement.
 26. The testing device according to claim 25, beingfurther configured to: when the test parameter during the firstcondition does not fulfil the requirement, verify that the communicationnode is not capable of operating during the first condition.
 27. Thetesting device according to claim 17, wherein the node setting, the testparameter measured during the first and second conditions are stored inat least one of: the communication node, the testing device and anexternal memory.
 28. The testing device according to claim 17, whereinthe test parameter is at least one of: Equivalent Isotropic RadiatedPower, Equivalent Isotropic Sensitivity, Timing Alignment Error, andfrequency stability.
 29. The testing device according to claim 17,wherein the first condition is a normal environmental condition and thesecond condition is an extreme environmental condition.
 30. The testingdevice according to claim 17, wherein the communication node is anActive Antenna System base station.
 31. The testing device according toclaim 17, wherein the test parameters in the first and second conditionsare Over The Air measurements using a reference antenna.
 32. The testingdevice according to claim 17, wherein the test location is a radiofrequency anechoic chamber
 33. A computer program product comprising anon-transitory computer readable medium storing a computer programcomprising instructions which, when executed on at least one processor,cause the at least one processor to carry out the method according toclaim
 1. 34. (canceled)